1 Introduction

Surgical site infections (SSI) are the leading cause of hospital readmission after surgical procedures [1] with significant impact on post-operative morbidity and mortality [2] Modifiable risk factors for SSI include procedural aspects, which include the possibility of instrument contamination, the duration of the operation, the number of people present and the traffic in the room [3], and the ventilation system of the operating theatre [4].

These factors influence each other because preparation of instrumentation involves processes that involve a certain number of operators, each step increases the risk in contamination, and the need for different instrumentation, depending on the type of operation, can lead to altered traffic in theatre.

The need to optimise infection control in OT is accentuated by the SARS-CoV-2 pandemic and the need to prevent and respond to future epidemics.

1.1 Research questions

  1. 1)

    What is the relationship between the features of surgical procedure sets and the frequency of surgical site infections (SSI) in patients undergoing surgical treatment?

  2. 2)

    How do the time frames of perioperative processes and operating theatre traffic vary in relation to the features of the procedure sets used?

  3. 3)

    What is the impact of streamlining and optimising surgical procedure sets and their direct and indirect costs?

2 Methods

This systematic review is conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses—PRISMA Statement 2020 [5].

Accordingly, the literature review process was carried out in the following stages:

  1. 1.

    Formulation of research questions by adapting the PICOS model

  2. 2.

    Developing a search string applied to databases;

  3. 3.

    Collection of identified records;

  4. 4.

    Screening of records according to inclusion criteria;

  5. 5.

    Full-text selection of the studies identified during screening;

  6. 6.

    Data extraction from the studies included;

  7. 7.

    Thematic analysis of results

2.1 Research strategy

The search was applied to the following databases: MEDLINE, Embase, Web of Science, CINAHL, The Cochrane Library.

The search string was formed by combining the following terms:

  1. 1.

    Procedure or procedural or surgery or surgical.

  2. 2.

    Tray or pack.

  3. 3.

    1 and 2

The complete search strategy can be found in Appendix 1.

2.2 Selection of studies

An initial screening was performed on the title and abstracts of the Records identified in the databases. Subsequently, the selected records were analysed on full text for inclusion or exclusion. The selection was made according to the following criteria:

  • Participants: surgical specialists, operating theatre (OT) nurses and nurse coordinators, theatre technicians, sterilisation centre (SC) coordinators and operators, other personnel with clinical, organisational, or logistical roles; patients undergoing surgical treatment

  • Intervention: use of conventional or disposable procedure sets; processes of rationalising surgical sets

  • Outcome: incidence of SSIs, procedure time, in/out traffic of personnel, costs related to surgical procedures

  • Setting: general and specialist surgery facilities, supply services and sterilisation centres (SC)

  • Study designs: qualitative, observational, nRCTs and RCTs, systematic reviews, guidelines

English-language studies published up to 28.12.2021 were selected.

Any previous guidelines, systematic reviews or meta-analyses discovered during the database search, concerning surgical sets from the point of view of clinical risk reduction, procedure optimisation and the rationalising of instruments, were selected and summarised in a separate table.

2.3 Data extraction

The data are extracted from the studies in a specially designed worksheet. Data were extracted on the test population, the surgical setting, the procedures performed, the operations and any follow-ups. The main operational outcomes of interest were:

  1. 1.

    A reduction in the incidence of post-surgical SSIs;

  2. 2.

    A reduction in procedure times;

  3. 3.

    A reduction in operating theatre traffic flow;

  4. 4.

    A reduction in costs associated with the intervention.

3 Results

Figure 1 represents the flow of the literature review effected. A search through PubMed, Embase, CINAHL, Web of Science and The Cochrane Library identified 5 865 records. Five further studies were added manually after consulting the bibliographies of the articles analysed. After eliminating duplicates, the remaining records were screened by title/abstract. 98 records were assessed as eligible and analysed on full text.

Fig.1
figure 1

PRISMA flow diagram

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A total of 62 studies were excluded from the complete analysis. In conclusion, 36 studies were eligible for inclusion in the review.

A complete list of selected studies and the relevant bibliography can be found in Appendix 2.

Excluded, reasons for categorisation: > 62:

  • full text not available (9): Littell 1951, Sebben 1988, Sheth 2003, Dieryck 1998, Stephanie 2010, Akridge 2004, Osborne 1999, Passey 2002, Wilkie 1986

  • Outcome not described or not of interest: (24) Ahmadi, 2019; Egan 2021, Baskett 2004, Bhumisorikul 2004, Costa 2018, Fogliatto 2018, Glaser 2015, Halbert 1988, Huang 2021, Kimse 2021, Kusuda 2016, Strulak 2021; Strzelecki, 1989, Torres 2021, Bradley 2019, Alfred 2021, Dana Barlow 2015, Holdsworth 2021, Igesund 2019, Navi 2012, Parker 2006, Wells 2017, Wells 2018, Eggleston 1997

  • No focus on surgical sets: (24) Agarwal 2019, Arslan 2018, Dilworth 1992, Edilich 1992, Fadaak 2021, Haya 2018, Johnson 2016, Kaygusuz 2003, Khurana 2018, Kong 1994; Kwaan 2016; Lin 2018, Martinez 2020; McDermott 2016; Meals 2007; Moccia 2020; Nguyen 2019; Panahi 2012; Rao 1992, Wagner 2021, Weiser 2018; Watters, 2011; Makram 2021, Olivere 2021

  • Study design not covered (e.g. editorials, case reports, opinion papers) (6): Reams 2013, Weber 1998, Nadeau 2018, O'Donnell 2002, Stephanie 2010, Goldberg 2019

  • Full text in other language (1): Blanc 2017

Including: 36:

  • Previous reviews on the subject (4)

  • Primary studies (32)

3.1 Summary of evidence prior to current review

Four literature reviews relevant to the scope of the current work were identified (Table 1). In particular, Dos Santos and colleagues [6] sought to understand the main techniques and approaches in the rationalising of surgical sets, the impact on financial and operational performance, and the knowledge gaps towards which research should be directed. The review identified many studies reporting signs of improved performance both operationally, concerning set assembly, OR management and ergonomics, and efficiently in terms of washing and sterilisation processes, repair, purchasing, set-up and professional education. The authors mapped an outline for future research. Salient points to be explored are: the promotion of consensus building in multidisciplinary teams, participation in surgical set rationalisation projects and consolidation of the progress achieved; technologies for instrument tracking; cross-surgical set analysis aimed at instrument reduction; relocation of instruments excluded from sets; how to measure “non-material” and “non-tangible” benefits of set rationalisation and set safety after the process; objectives following the establishment of a surgical set rationalisation cycle.

Table 1 Previous systematic reviews
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A systematic review [7] analysed the problem of contamination of implantable instruments and devices in spinal surgery. Many studies have shown significant contamination rates. Preoperative factors, mainly related to sterilisation and device handling processes, and intra-operative factors, more dependent on personnel procedures, were noted. With respect to pre-operative factors, several studies question the overall effectiveness of sterilisation alone. At the same time, recommendations for device reprocessing are recognised as being difficult to implement in clinical settings. Regarding intra-operative processes, studies emphasise the importance of preventive practices such as changing gloves before handling implant materials, because the risk of contamination increases with exposure time [7].

3.2 Clinical interventions to prevent surgical site infections

Three observational studies report direct evidence of an effect on the incidence of SSI (Table 2). A cohort study conducted on 233 women with ovarian and uterine neoplasms who underwent colon surgery showed a statistically significant reduction in SSIs 30 days after surgery after implementation of a preventive bundle targeting the surgical wound closure phase, including the use of a separate surgical set [10]. Two other observational studies investigated the use of disposable sets versus traditional reusable sets. The first, conducted on neuro-surgical patients undergoing lumbar fusion, observed a reduction in the incidence of SSIs from 6% in the series of 100 patients treated with reusable instruments to 2% in the series of 49 patients treated with disposable sets (p < 0.001). A significant reduction in surgical procedure duration (p < 0.05) and functional recovery time (p < 0.001) was also observed [11]. In the second, 449 orthopaedic patients underwent total knee arthroplasty using single-use instrumentation and only 0.2% underwent revision surgery for SSIs, compared to 3% (p < 0.006) of cases in a series of 169 patients operated on with conventional instrumentation [12].

Table 2 Clinical interventions to prevent surgical site infections
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3.3 Procedures for surgical tray rationalisation

Twenty-nine surgical tray rationalisations (STR) as part of quality improvement projects aimed at creating an optimised set for specific procedures.

In this context, unused items were removed from the instrument management process.

The studies presented in the literature (Table 3) involved multiple branches, including: orthopaedics (n = 6), gynaecology (n = 4), ENT (n = 6), thoracic surgery, endocrine surgery, paediatric surgery (n = 2), neurosurgery, ophthalmology, vascular surgery, breast surgery (n = 2), urology, general surgery (n = 2), hand surgery, and plastic surgery. Several studies included an observation phase involving the preparation, use and reprocessing of the surgical sets between the operating theatre (OT) and the sterilisation centre (SC) (n = 13).

Table 3 Procedures for rationalising traditional surgical trays
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3.4 Processes

The rationalisation process was preceded by training and sessions to raise awareness (n = 3) aimed at increasing the degree of motivation for change and overcoming resistance that was potentially risky for the entire process.

The extent to which an instrument is used, and therefore the benefits of keeping it in the set or not, was assessed on an objective basis by analysing the data collected during the observation (n = 13), with the cut-off of use generally considered to be 20% to 25%. In other cases, the selection was made on a subjective basis by professionals (n = 3), by consensus or the collection of questionnaires on perceived use. In one case a heuristic mathematical model was developed based on a discussion with skilled surgeons on their preferences as to the composition of individual sets [10]. The model was then tested on the operating division agendas with the goal of cost-cutting.

In some cases, only surgeons were involved (n = 6). In other cases, the formation of a multidisciplinary team was promoted (n = 7).

In most of the studies, the new optimised set was presented to the clinicians for review. Devices or instruments were then added based on their opinion.

Surgical devices or instruments that were excluded were generally packaged in a dedicated set, or the original set remained available and the frequency of use of the instruments excluded was used as a marker of the safety of rationalisation.

Some studies considered a follow-up aimed at assessing the degree of satisfaction with the new rationalised set after a period of time (n = 3).

3.5 Outcomes

The outcomes analysed were mainly of three types:

  • reducing the size of the set and the number of instruments (Table 4);

  • reduction of peri-operative and sterilisation times and reprocessing of sets (Table 5);

  • reduction of direct and indirect costs related to the procurement, replacement and reprocessing of instrumentation (Table 6).

Table 4 Outcome of rationalisation of surgical sets relative to instrumentation
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Table 5 Outcomes of rationalisation of surgical sets related to time
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Table 6 Cost-effectiveness of rationalising surgical sets
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Therefore, the studies reported primary outcomes having an impact on the organisational framework.

18 studies indicated a reduction in the number of instruments from the original set to the optimised set. As five of these studies involved the optimisation of more than one set, they either reported a separate outcome for each set (n = 3) or an average value across sets (n = 2). Of the total number of items analysed, the percentage reduction in the number of instruments per individual set ranged from 19 to 89%.

In 10 studies, the observation phase in OT described the utilisation rate of the individual sets observed. Utilisation of instruments before optimisation ranged from 12.5% to 66%.

One study reported a comparison between the utilisation rate before and after the optimisation of two sets, showing an increase in use of between 27 and 30% [13].

One study analysed the difference between the perceived use of surgical devices and instruments by the surgeons involved and their actual use determined by observation, which were respectively 37% and 55% [12].

Seven studies measured the frequency of reopening the original set in a predetermined period after optimisation. Considering that a total of eight sets were optimised, in five instances no reopening events were recorded, in the other cases the frequency of reopening was 0.9%, 6% and 10% respectively.

One study measured a reduction in the frequency of procedure cancellations following the introduction of an optimised set: incidents dropped from 3.9% to 0.2% [16]. The same study submitted a questionnaire to gather indications of staff satisfaction with the instrumentation before and after optimisation, with an increase from 1.7% to 80% [13].

Eleven studies measured the time taken to set up the operating theatre, which decreased to 2 from 5 min following the introduction of optimised sets. Other studies observed that optimisation of the set had an impact on the overall duration of the procedure, with a 5 to 6-min reduction. A reduction in the time spent cleaning the operating theatre (-25%, n = 1), and time spent by the nurse on duty outside the theatre for reasons related to retrieval of surgical instruments (-15.5%, n = 1), were also observed. One study observed downtime of 9% of the entire procedure for reasons related to locating surgical instruments [14].

Concerning costs, many studies have estimated projected cost savings in the procurement, sterilisation and processing of instruments. The average annual savings were estimated at $1 525.00 to $2 800 000.00 (n = 12), depending on the activity flow of the various hospitals involved.

Differences in estimated savings were observed depending on the differing procedures: from $55.00 to $310.00 per single procedure [15,16,17].

4 Discussion

The results of the systematic review brought to light observational studies that can be divided into two categories: evidence of purely clinical significance and evidence of mainly organisational, managerial, and financial significance. These two systems are largely interconnected, and reciprocally influence each other.

The decision to use disposable devices and instruments has been accompanied by a lower incidence in surgical site infections and surgical revisions for remediation. A concomitant reduction in post-operative functional recovery time has also been observed [11].

The rationalisation of traditional surgical sets has been observed in conjunction with outcomes of organisational significance, some of which could have an indirect clinical impact. As already highlighted by previous reviews, intra-operative time and time spent by nurses outside the room, as well as the reduction of setup time[7, 8] could lead to a further reduction in the time window of infection risk. Similarly, air movement in the operating room, potentially risky for contamination, could be reduced. However, studies reporting clinical outcomes as a direct consequence of organizational factors have not been found.

The effectiveness of the rationalisation of surgical sets seems to depend mainly on two conditions: the type of surgery, including the different access modes possible; and the organisational model followed. The main models observed in the interventions were Lean management and Kotter's change model. Responsibility for a training and awareness-raising process, with the active involvement of all stakeholders, appears to play a decisive role in practitioners’ participation in rationalisation practices and the long-term maintenance of the results obtained.

4.1 Limits

The observational nature of all the studies identified means that the evaluations resulting from this review can be generalised taking into account the specific organisational context. This implies the need to promote future research on the topic by way of a context-specific analysis. In this context, research should consider the elements mentioned by Dos Santos and colleagues [6]: the promotion of increased consensus in multidisciplinary teams, participation in surgical set rationalisation projects and consolidation of the progress achieved; technologies for instrument tracking; a cross-sectional analysis of surgical sets aimed at instrument reduction; relocation of instruments excluded from sets; how to measure the 'non-material' and 'non-tangible' benefits of rationalisation and set safety after the process; and objectives following the establishment of a surgical set rationalisation cycle. Furthermore, clinical practice could benefit from primary or secondary research design that can exemplify outputs as a result of modelling that includes an analysis of clinical or organisational improvement in relation to specific organisational, cultural and functional frameworks. It should be noted that most of the quality improvement interventions analysed did not investigate the association with direct clinical outcomes on patients such as ISS incidence, mortality and morbidity, or the occurrence of other complications, due to the nature of the project, which is also exempt from ethical approval,due to the nature of the project which was also not accompanied by ethical approval. It is considered important that organisational process indicators go hand in hand in the future with an analysis of the direct effects in the clinical field, in order to further clarify the value of the processes considered.

Most of the studies were carried out in single centres. This implies, especially as regards rationalisation of surgical sets, that the results are extremely sensitive to the organisation of individual healthcare facilities and their catchment areas.

Cost estimates presented in studies have been developed retrospectively and in some cases according to direct case-by-case analysis. These projections may be sensitive to variables not examined, including the type and overall availability of instruments in the market, and may not be generalised regardless of the country in which the study was carried out.